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Microbial contamination associated with routine aseptic practice
N A Klapes1, V W Greene, A C Langholz
1University of Minnesota, Division of Environmental and Occupational Health, Minneapolis 55455.
Abstract:
We have studied the rate of fortuitous contamination associated with routine aseptic technique under operational conditions. Stainless steel strips, as simulators of surgical instruments, were contained in sterilized surgical packs and assayed by nursing personnel during surgical and other invasive procedures at three different hospitals. The rates of contamination observed for the 36 investigators ranged from 0% to 11.3%, with an overall rate of 2.7%. Assays conducted in a clean room environment, under conditions approaching industrial sterility standards, showed a contamination rate of 0.16%. We concluded that aseptic practices, as routinely performed without any noticeable breaks or transgressions, do not guarantee sterility. The concept of surgical sterility implies low level, but measurable, microbial contamination.
Insights
Routine aseptic technique in hospitals results in a 2.7% contamination rate, indicating that even without observed breaches, surgical sterility is not guaranteed. Microbial contamination is a measurable, low-level risk in clinical settings.
Area of Science:
- Microbiology
- Healthcare Infection Control
- Surgical Sciences
Background:
- Routine aseptic technique is fundamental in preventing surgical site infections.
- The effectiveness of aseptic practices under real-world operational conditions requires continuous evaluation.
- Understanding contamination rates is crucial for optimizing sterile processing and patient safety.
Purpose of the Study:
- To quantify the rate of fortuitous microbial contamination during routine aseptic technique in clinical settings.
- To compare contamination rates in a hospital environment with those achieved under industrial sterility standards.
- To assess whether current aseptic practices guarantee complete sterility.
Main Methods:
- Stainless steel strips, simulating surgical instruments, were placed in sterilized surgical packs.
- Nursing personnel assayed the strips during routine surgical and invasive procedures across three hospitals.
- Contamination rates were analyzed based on the 36 investigators and compared to cleanroom assays.
Main Results:
- Observed contamination rates among 36 investigators ranged from 0% to 11.3%, with an overall average of 2.7%.
- In contrast, assays under industrial cleanroom conditions yielded a contamination rate of 0.16%.
- These findings highlight a significant difference between idealized and operational sterility.
Conclusions:
- Routine aseptic technique, even when performed meticulously, does not ensure complete sterility.
- Surgical sterility should be understood as a state of low-level, measurable microbial contamination.
- The study underscores the need for ongoing vigilance and potential improvements in aseptic protocols to minimize microbial exposure.